Variable condenser



June 14, A1927e 1,632,650

F. O. HARTMAN VABIABLE CONDENSER Filed Dec. a, 1925 5 Sheets-Sheet l Jun@ 14, 1927., F. O. HARTMN VAMABLE GONDENSER Filed Dec.. a, 1925 5 sheets-Sheet 3 IN V ENTOR.

Patented June 14,` 1927.:

Y FRANK o. mwN, or

m5112131), OHIO, ASSIGNOR TO HABTMAN ELECTRICAL MANUFACTURING GOHPAINY, Ol? MANBFIELD, OHIO, A CORPORATION F OHIO.

* -ABIABLE CONDENEB.

. 'Application fled December My invention relates broadly to electrical, tuning apparatusand more particularly to a construction of variable condenser for controlling a plurality of electrical `circuits simultaneously. U

One of the objects of my inyention is to provide 'a construction of multiple variable 4cmdenser in which a plurality of sets .of rotor plates are arranged to cooperate with aA-a' plurality. of independent sets cip-stator plates, -the stator p1atesbe1ng supported upon a'base with means for adjustmg the n osition of the sets of stator plates upon the ase for compensating for differences in the electrical circuits which the apparatus is arranged to control. y l

Another object of my invention is to provide a construction of multiple variable condenser in whichY a supporting plate member se is provided with a track portion in which sets of stator plates may be adjusted in position with respect to sets of rotor plates which are driven from a common shaft, the sets of stator plates being independently adjustable for compensating for variations in the 'capacity of the electrical circuits which the variable condenser is arranged to control.

Still anotherobject of my invention is to )rovide mechanical means for initially ad- ]usting the position of sets of stator platesupon a common supporting member to cooperate With sets of rotor lates in such manner that the dierences in capacity betweefn the.' several sets of stator and rotor plat'os may be compensated for by shifting the position of the sets of stator-plates.

.A further object of my invention is to construct a multiple variable condenser in such manner that sets of stator plates may be shifted circumferentially around a common rotor carrying lsets of rotor plates arranged to be interleaved in varying degrees With the sets of stator plates ior compensating ordiierences in the electrical capacity of circuits in which the sets ofstator and rotor plates may be connected. c:

' My invention finds particular application as a single control tuning system for multistage electron tube radio requency am li- ,o iiers where theinput circuits oi a plura ity o'tubes may be adjusted simultaneously under control of a sine'le rotatable member,

desire that it be undberstood however thatv the variable condenser construction of my intention-"may .be .utillzednn a. number of 8, 1825. Serial No. 74,158.

different types oi circuits and that my invention is not limited to the' application of the variable condenser construction as a tuning unit in a radio broadcast receiver apparatus.'

M invention will bemore clearly understoo from the specification hereinafter following by reference to the accompanying drawings, wherein:

VFigure l is a front view of the support which carries the sets of stator 'plates in the variable condenser construction; Fig. 2 is a rear view of the variable condenser construction of my :invention showing the mounting of the sets of stator plates in an annular track in the rear of the supportin plate member; Fig. 3 is a side elevation o the multiple variable condenser of my invention; Fig. 4 is a cross-sectional view taken through themultiple variable condenser on line 4.-4 of Fig. 1 with the bearing for the control shaft'shown partially in si e elevation; Fig. 5 is a cross-sectional view taken through the variable condenser construction on line 5-5 of Fig' Fig. 6 aoA is a detail View of the mounting o 4one of the sets of stator plates on line 6-6 of Fig.

l; and Fig. 7 is a fragmentary cross-sectional view taken on line 7--7 of Fig. 1 showing the mounting of another of the 35 sets of stator plates in the multiple variable condenser.

In a radio receiving system in which my invention may be ap lied a radio frequency f amplifier is general y employed having a plurality of independently .,uned circuits and it is usual to adjust .each of the circuits independently for securing proper resonance for the frequency of the incoming signaling energy. By my invention I providea tuning clement by which all of the several independently tunable circuits may be tuned simultaneously by operation of a single control. I provide a mounting for a plurality oi' sets oi' stator plates into which a plu- 100 rality of sets of rotor plates may interleave Witli the sets of stator plates so arranged on the mounting that they may be independently adjusted in position with respect to the sets o'l' rotor plates so.thatdif-' 105 fer-ences in the electrical capacity existing in the several associated circuits ma be compensated for by shitting the position of the sets oi' stator plates with r `t to 'the sets rotor plates. The set/apo?, stator nu,

plates are initially placed in selected positions by factory test of the apparatus after lwhich the proper relationship of the physi-` reference c aracter 1 represents the suprt' late on which the parts of the lbltlilple Pvariable condenser are mounted. The supporting castin as shown aving radial strengthening ri or fins 2 with a bushingmember extending centrally from the rear of the plate as represented at 3. The bushing member forms a means of support for the central screw member 4 which extends perpendicular to the lane of the su porting late 1. Ahead 5 is provided on t e memr 4 with a Washer member 6 secured thereunder and a. resilient bearing plate 7 fastened under the washer member 6 engaging with the rear plate 8 ofthe rotor. The rotor com rises sets of laterally projecting plates 29 0 and 31 which are spaced froml each other by'means of fiat spacin members 10 and secured together in a stac by means of bolt members y12 having their ends secured in plate. 9 toothed at its peiipher in the form of a gear. The sets o rotor p ates are spaced from the ear 9 by means of washer members 11. he rotory is driven by means of a pinion 14 en aging the teeth of the ear'member 9. T e pinion 14 is carried y a shaft 15 which is journaled in a bearing member 16. The bearing inember 16 is in tbe form of 'a rectangular block fitting in an aperture 22 in aspacin strip 20 and passing through an elonga aperture 23 in an opposite spacin stri 21. A bushing member 19 is secure to t e rotatable shaft 15 and abuts against the ends of the bearing member 16. A-knob 18 is provided for rotatably driving the shaft 15.

A 4block member 24 is secured by screw member 44 to the supporting plate 1, the screw member 44 passin through an a e1'- ture in the spacing strip 20. The bock member 24 provides an end support for the spacing strip 21 by which the operating parte of the driving system are positively centered. The block member 24 is provided with an ad'usting screw 25 passing therethrough an engaging the bearing memberv 16 forI properly fixing the en agement between pinion 14 and ear 9. he supporting plate 1 isl provi ed with an annular v tracl35 cast into the plate and adjustably positioned around the track 35 I provide curved stripmembers 36, 37 and 38 torming Individual sup orts for the sets of stator plates 32, 33 an 34. The set of stator plates 32 is mounted upon bolt members 32 and 32 which are embedded in insulated bushings 32 and 32", -the bushings being of the supportin late may be a circular` spaced by a curved strip-like member 87 which fits within the annular trlckl. strip-like member 41 curved in .ga mannerl similar to the curvature of the strip-like member 37 is provided on the opposite side plate 1 with screw members 32 and 32 passing through the supporting plate v1 and into the nsulatedbus ings 32d ,and 32. The heads of the members 32' and 32l restagainst resilient washers engaging the face of the curved strip-like member 41. The supporting plate l is provided with elongate a rtiires 48 and 49 in which the screw mem rs 32e and 32' may be laterally shifted in either direction b loosening tbe screw member 47 permitting the curved strip-like members 37 and 41 to be moved around the annular track 35 to a position at which the sets of rotor plates are properly'interleaved with' the corresponda rsets of stator lates.

The set of stator p ates 33 is carried by bolt members 33* and 33 which are embedded in insulated bushings 33 and 88. The bushings 33c and 33d are spaced a art` by means of curved stri 36 which sides within the annular trac 35 to cooperate with a similar curved strip 39 on the opv posite side of the supportin plate l, Screw members 33 and 33 pass t rough elongated apertures 46 and 45 inthe supporting plate 1 enabling theset of stator plates 33 to be shifted in position. A lever 42 is fulcrumed at a point adjacent the end of the spacing strip 20. The lever 42 has its end pivotally mounted at screw member 44 and has a ivotal connection 43 with the curved strip- 'ke member 39 whereby `the complete set of stator plates 33 can be shifted in position in either direction when the set is initially calibrated or compensated for di'erences in electrical capacit in the several circuits under factor adJustment.

The set ofY position on bolt members 34l and 84" and a art on the curved strip member 38 slidib. e in the annular track 35. On the opposite side of the su porting plate 1 there 1s rovded a curve stri 40 which may be s iftstator plates 34 is mounted in U0 embedded in bushings 34 and 34 spaced ed circumferentia y by reason of, screw u plates may be given anylde- :lessees 8 mounting tlO stator nded list to the d are shifted i sets of vstzutor plates 3L un e s s. lie position of tile sel; oit stator plete 3? however may be varied 'Jy tbe operator of tire receiving apparatus after installation of tlie apparatus ,tor matching up tlre receiver for e perticuiar antenne, installation. Tbst is to sey the stator plates 33 connected iottlie priresry tuning eircuit ot the receiver and tbe lever provided for shifting' the position of tbe set si stator pistes 33 or allowins' circuits to be compessoted 'for in .tierent di'eresces,

After 'having oncel roetelied 'tbe receiver to tlic antenne inst-filiation and rosintsining tbe factory adjustment of 'l e other sets of stetor 'isaletesconstent,sitnn neous control or' i several circuits of t e 'receiver may e secured undertbe rotative movement of control t8.

lallsile l lieve deseribe-:l my :invention in serein preferred embodiment ll desire tiret it be ugderstood that modifications may in detail Without departing from .l et my invention .and that s intend tiple variable condenser, tbe e, "ilste, sets ot iourrislcd tive movement orting plete, independent sets l Looper 'te with es, seid of pistes being sl Y position on seid s'iipporting plete around 'the jiosrnel oi' seid rotor es center wir .oy seid sets oft rotor pistes enter wel of stator plates ist ering positionsxn 2. ift multiple `fesrisble con comprisin eombiuetion e supp l plerslity sets of rotor ple mounted 'for rotative movementivitli .respect to seid paneli s plus.

T movable carriers mounted upon said. panel, e plurality otsets o stator pistes supported by eseli et seid carriers erreiiged to cooperate itli seid sets or rotor plates, seid sets ci? stator being siiifteble on seid carriers within e circuler path tot varying tb'e positions which tbe sets of rotor pistes enter the eoopersting sets of stator piet lie e multi-ple verts-rele' e.

eoutrollisg s plnrslity electrics-v .s

ug panel,

simultaneously, tbe combination of a multiple number ol' sets otl rotor plates, a corresponding nun'iber oi sets of stator plates 'for cooperating with said sets ot rotor plates, individual carriers for ein-li ot' said sels of stator platos, said sels ot' sinlor plntcs being sliilzibly mounted on ,ssiil carriers with respect to sind sets oi rotor pistes for udjusting tlxe relative positions in which .seid

plates, individual supports for each of said,`

sets of stator plates, said sets'of stator plates being shittable in either direction around the exis of ssid rotor plates on said individual supports 'for adjusting the relative posi-- tions in which seid sets of rotor plates enter said sets ot stator plates.

ln e multiple variable condenser for controlling a plurality of electrical circuits simultaneously, the combination of a multiple number of sets of rotor plates, s corresponding number of sets o stator plates for cooperating with seid sets of rotor plates, s stspporting plate common to both of said sets of rotor and stator plates, and mes-ns on said supporting plate for advancing or retreating each of seid sets of stator plates with respect to each ot said sets of rotor plates 'lor fixing the relative positions et which said sets ot rotor plates enter said stator plates.

6. lne n?. ltiple variable condenser or controlling s plurality of electrical circuits simultaneously, the combination of a multiple number of sets o rotor plates, a. corresponding number of sets of stator plates for cooperating with said setsv of rotor plates, s supporting plete common to both seid sets ot' rotor and stator plates, and individual plete members ou seid supporting plate for slidably mounting escli of said sets ,of stator plates with respect to said sets of rotor pletes whereby tbe position of said sets of stator plates may be independently fixed with respect to the entrance therein o cooperating sets of rotor plates.

i'. ln s multiple variable condenser for controlling e plurality of electrical lcircuits simultaneously, the combination of a multiple number of sets of rotor plates, e corresponding'number of sets of-ststor plates for cooperating with said sets of rotor plates, supporting plete common to both said sets f orotor and stator plates, an annular track on said supportin' plate and means carried positioned in said annular track'l v vheeby seid. sets of stator plates may be shlfted m 

